This invention relates to an intrusion detector device for signalling the undue opening of doors and closing-wings in general.
The action of house breakers in breaking open doors notably consists of inserting a crowbar between the doorjamb and door to force the bolt out of its insertion seat.
To signal this method of housebreaking, locks have already been proposed having a bolt which, when thrust transversely by the crowbar force, becomes obliquely disposed in opposition to elastic return means, so as to close a switch which controls an electrical alarm apparatus.
The need to support the bolt in an articulated manner to enable it to become disposed obliquely during forcing evidently renders the structure of the lock very complicated, because of which this type of lock has very considerable economical disadvantages.